Dworkin on Hart

According to Hart, judges decide cases in one of two ways:

  1. They apply legal rules to the facts in the case before them.
  2. They exercise discretion and legislate, revising the rules to give an answer to the case before them.

Dworkin believes that judges settle cases in at least one of these two ways:

  1. They apply legal rules to the facts in the case before them.
  2. They apply principles to the facts in the case before them.

The primary goal of Dworkin’s article is to show two things.

  1. Principles play a significant role in judicial decision making.
  2. Hart’s theory that the law is the union of primary and secondary rules cannot accommodate principles.

What about judicial discretion?

I am not sure that I understand what Dworkin thinks about judicial discretion as a source of law. Having thought about it for most of the morning, he might be in more trouble than I had appreciated. Let me explain.

We got into this because of questions about judicial discretion as a source of law. The realists moved too quickly from the fact that some judicial decisions are not determined by rules to the conclusion that judicial decisions are needed to settle the meaning of all laws. That is what Hart means when he warns against being “preoccupied with the penumbra” (Hart 1958, 615). Nonetheless, Hart agrees with the realists that judges have to make law at least some of the time. That is the lesson of the law that prohibits vehicles in the park: judges have to determine what counts as a vehicle for the purposes of the statute (Hart 1958, 607).

We ended our discussion of Hart with some dissatisfaction about this aspect of his view. He did not say enough about how judges legislate or how they balance conflicts between law and morality.

Dworkin’s principles might fill some of the gaps. For example, they suggest a way that at least some moral ideas might be incorporated into the law. The judges in Riggs v. Palmer found that the law contains the principle that no one should profit from their own wrongdoing. That enabled them to avoid saying either that they were ignoring the law because it was immoral or that they were doing something immoral because it was required by the law.

However, I do not see how principles could be used to decide all of the cases in which Hart and the realists think judicial discretion is needed. Is there a principle that settles the question of whether a rickshaw counts as a vehicle for the purposes of the statute forbidding vehicles in the park?

So I am not sure what Dworkin thinks about judicial discretion as a source of law. I know he thinks that principles cannot be incorporated into the law by judicial discretion (see Dworkin 1967, sec. V). A natural extension of his arguments for that point would lead to the exclusion of judicial discretion as a source of law in all cases. But, again, I do not understand how that would work. Perhaps that is a problem for Dworkin.

Principles and rules

Dworkin tried to show that Hart faces a dilemma. He has to choose between saying that principles are part of the law and saying that they are not part of the law. Neither alternative is palatable for Hart and there is no third option.

We were quick with the first option, that principles are not part of the law. Hart had drafted a response to Dworkin that was published in the postscript of the second edition of The Concept of Law (Hart 1994). While Hart’s remarks were incomplete, his comments all concerned the second option, so that’s where we concentrated our attention.

Following Hart’s postscript, I noted that the rule of recognition could be used to identify some of what Dworkin calls principles as part of the law. Whatever rule of recognition is employed in the US clearly includes the Constitution as part of the law and the Constitution also clearly has parts that are more like principles than rules.

However, this is not enough for Hart’s purposes. He needs to show not just that his theory could explain how some principles are part of the law but that it could show how all of them are part of the law.

Dworkin expressed skepticism that this could be done. It is not as easy as saying “whatever is passed by the legislature (following the rules, etc.) is law.” Nor would it do to have something empty like “the principles that count as law are the ones that are accepted as counting as law.” That says nothing about how to recognize the principles that belong to the law and distinguish them from those that do not.

At the end of the day, Dworkin and Hart approach principles from two different directions. Dworkin thinks that the origins of principles are irrelevant; it’s their substance, specifically their appropriateness, that matters. For Hart, it’s the other way around: laws are determined by their origins. For Hart, a law is a rule that comes from a source that can make laws, no matter how stupid the rule is. For Dworkin, a principle has to make sense, no matter what its source is or even if it has no identifiable source at all.

Ex post facto legislation

One point Dworkin made against the positivists (and the realists) is that if judges are legislating, then the parties whose cases are being decided are being punished based on the law that is made after they did the things that brought them to court.

That seems pretty bad. How can it be fair to require people to comply with laws that did not exist when they were deciding what to do?

At the same time, however, I’m not sure Dworkin himself has a solution to this problem. According to him, judges settle questions about legal rights and duties by consulting an indeterminate mass of principles whose interpretation and weight are matters of judgment. Here are three things he said about how judges use principles.

We argue for a particular principle by grappling with a whole set of shifting, developing and interacting standards (themselves principles rather than rules) about institutional responsibility, statutory interpretation, the persuasive force of various sorts of precedent, the relation of all these to contemporary moral practices, and hosts of other such standards. (Dworkin 1967, 41)

If … we tried actually to list all the principles in force we would fail. They are controversial, their weight is all important, they are numberless, and they shift and change so fast that the start of our list would be obsolete before we reached the middle. (Dworkin 1967, 45)

Once we … treat principles as law, we raise the possibility that a legal obligation might be imposed by a constellation of principles as well as by an established rule. We might want to say that a legal obligation exists whenever the case supporting such an obligation, in terms of binding legal principles of different sorts, is stronger than the case against it. (Dworkin 1967, 45)

It seems to me that people trying to comply with the law can be just as much in the dark about how their cases will be decided if judges use principles as they would be if the judges make the law up in deciding the case.

So one thing I take away from this discussion is that we have an ideal that probably cannot be met. Our ideal is that the law is settled in advance such that it is possible for someone who is sincerely trying to comply with the law to do so. But there may be areas of the law where private citizens cannot know if they are in compliance or not because what the law is is too unsettled.

The realists had a pretty good point!

Key concepts

  1. Principles vs. rules
  2. Why it seems difficult to formulate a rule of recognition that could include principles
  3. The problem of ex post facto (or retrospective) legislation for both views


Dworkin, Ronald. 1967. “The Model of Rules.” University of Chicago Law Review 35 (1): 14–46.

Hart, H. L. A. 1958. “Positivism and the Separation of Law and Morals.” Harvard Law Review 71 (4): 593–629.

———. 1994. The Concept of Law. Second edition. Oxford: Clarendon Press.